I have 2 San Disk 4 GB pen drives(pendrive1,pendrive2).My computer have 3 usb ports(port1,port2,port3).My problem is that,one of my pen drive(pendrive1) is not even detected in the port1 and port2,but its working in port3. Other pen drive(pendive2) is working in all the three port.i am running windows Xp pack 3.I have tried to re install USB Hubs ,safe mode etc. nothing works.I don't know what is blocking that pen drive.Please help me